Switch



Dec. 15, 1936. I A. RAMSEY SWITCH Filed April 19, 1930 6 Sheets-Sheet lDec. 15, 1936.

A. RAMSEY 2,063,954

SWITCH Filed April 19, 1950 6 Sheets-Sheet 3 Dec. 15, 1936.

A. RAMSEY 7 2,063,954

SWITCH Filed April 19, 1930 6 Sheets-Sheet 4 Dec. 15, 1936.

A. RAMSEY SWITCH Filed April 19, 1930 6 Sheets-Sheet 5 l I l I l l Dec.15, 1936. RAMSEY 2,063,954

SWITCH Filed April l9, 1930 6 Sheets-Sheet 6 avg Q Patented Dec. 15,1936 UNITED STATES PATENT OFFICE assignments, to Schweitzer & Conrad,

Inc.,

Qhicago, 111., a corporation of Delaware Application April 19, 1930,Serial No. 445,548

65 Claims. (01. 200-162) This invention relates to electric switches andWhile it is of general application, it is particularly applicable todisconnect switches.

In the design of disconnect switches of very high current carryingcapacity certain problems arise which do not arise in the design ofswitches of lower current ratings. For instance, other things beingequal, the heating of a switch is proportional to the square of thecurrent carried thereby and increases directly with the electricalresistance of the switch. The electrical resistance is a function of thetemperature and increases as the temperature increases. Thus anyincrease in the current carried by the switch would of itself result ina heating of the switch, which heating would result in an increase inthe switch resistance, thus causing further heating. At the point ofengagement between the switch blade and the switch contact there isbound to be a certain amount of electrical resistance. The greater thecurrent flow the more heat there will be developed at that contact;hence the problem of reducing the contact resistance and of increasingthe rate of heat radiation becomes of great importance as the currentrating of the switch increases. Disconnect switches are infrequentlyoperated, hence the blade and the contact may both become coated withoxide or other impurities while the switch is open. Upon closure oftheswitch this must be scraped away since such impurities are ofcomparatively high resistance.

It is one of the objects of the present invention to provide a switchwherein there is a cleaning action as the switch is closed and whereincontact resistance is reduced and heat radiation is greatly facilitated.

I have invented a switch which operates on the principle of makingcontact between the movable blade and the stationary clips at arelatively large number of points, each having a comparatively smallarea, instead of making contact through one or two fiat surfaces of arelatively large area as in the conventional type of switch.

In one embodiment of my invention the contact clip comprises a largenumber of wires which are simultaneously engaged by the blade. The wiresare preferably arranged in two rows, al though the invention is notlimited to such an arrangement since a greater or a lesser number ofrows may be used if desired. Each wire is fastened at one end and islocated in the path of movement of the switch blade so that the bladeslides over the wire, the wire being. maintained in firm contact withthe blade by its own resiliency. The opposite end of each wire is preferably permitted a limited amount of motion and normally lies in the pathof movement of the blade. As the blade is moved to the closed positionit forces the free end of the contact wire out of its path, the bladesliding along the contact wires. This sliding action takesplace over acomparatively small area and there is a considerable pressure betweenthe sliding parts, with the result that the sliding is accompanied by ascraping or cleaning action which removes all oxide and other foreignmatter. The contacting surfaces are thus always clean and the contactresistance is reduced to a minimum. The contacting portion of the switchblade is preferably made convex to further decrease the contactin areaand thereby increase the unit pressure at the contact.

In another embodiment of my invention the blade consists of a largenumber of laminations spaced from one another to facilitate heatradiation and arranged to make contact by a wiping motion crosswise ofthe laminations whereby impurities that may be present are scraped awayand clean contacting surfaces are presented.

It is a further object of the present invention to provide an improvedswitch lock for locking the switch against opening due to the forcesthat may be present during extremely heavy current flow, such as maytake place during short circuiting conditions. The blade consists of twoparallel blade members secured together in spaced relationship by meansof spacing pins or-the like. A latch is mounted on the stationarystructure for engaging one of the blade spacing pins to lock the switchagainst being blown open by excessive current flow. The blade isprovided with a pivoted pull ring which has a cam portion that engagesthe latch upon the initiation of the switch opening motion and it movesthe latch to the released position. The latch and pull ring are of avery simple design and may be used for either single throw or doublethrow switches. The eye of the pull ring is shaped so as to allow aprong or switch stick tobe inserted therein and initially apply its pullas far as possible above the center of the blade when actuating theswitch to the open position.

A further object of the invention is to provide a high pressure multipleswitch contact comprising spring contact elements that are under initialtension, that is, prestressed.

By placing the contact fingers, such as the wire members or similarspring members under initial tension by lateral displacement, andholding them from expanding to their unstressed position, it is possibleto secure a high spring pressure with a very small amount ofdisplacement. The effect of closing the switch is merely that oftransferring the spring pressure from the stop to the blade or armcontact. As the spring contacts require only minute displacement to makethe transfer of pressure, the switch is closed easily and without dangerof stubbing the contact fingers.

Since the resistance of a contact decreases with increase of unitpressure of the engaging surfaces, the practical advantage of gaininghigh unit contact pressure with small lateral displacement is obvious.This is particularly important in switches where a rigid switch contactand a multiple spring contact are brought into engagement in therelation of an arm or tongue thrust between gripping jaws, or viceversa.

The attainment of the above and further objects of the present inventionwill be apparent from the following specification taken in conjunctionwith the accompanying drawings showing a few proposed embodimentsthereof.

In the drawings:

Figure 1 is a top plan view of a switch constructed in accordance withmy invention;

Figure 2 is a side elevation thereof;

Figure 3 is a sectional view taken along the line 3-3 of Figure Figure 4is a view similar to Figure 3 showing the position of the clip when theswitch is open;

Figure 5 is a fragmentary sectional view of the contact clip and latchmechanism when the switch is closed;

Figure 6 is a fragmentary top view of one of the contact clips prior tothe insertion therein of the contact wires;

Figure 7 is a section taken along the line 1-1 of Figure 2 and lookingin the direction of the arrows;

Figure 8 is a view similar to Figure 4 showing a somewhat modified formof contact clip;

Figure 9 is a sideview of the hinged portion of a somewhat modified formof switch;

Figure 10 is a top plan view of another form of the switch constructedin accordance with my invention;

Figure 11 is a side elevational view of the switch shown in Figure 10;

Figure 12 is a section taken along the line I2 I2 of Figure 11;

Figure 13 is a sectional view taken along the line I3-I3 of Figure 11;

Figure 14 is a sectional view taken along the line I4I4 of Figure 12; pFigure 15 is a top plan view of another switch constructed in accordancewith my invention;

Figure 16 is a side elevational View of the switch shown in Figure 15;

Figure 16a is a view of one of the laminations constituting the switchblade;

Figure 17 is a sectional view of the hinge contact of the switch ofFigure 16, said view being taken along the line I1i'l of Figure 16;

Figure 18 is a view taken along the line l8-I8 of Figure 16, looking inthe direction of the arrows;

Figure 19 is a sectional view taken along the line I9-I9 of Figure 16and looking in the direction of the arrows; and

Figure 20 is a fragmentary sectional view taken along the line 20-20 ofFigure 15.

Reference may now be had more particularly to the form of switch shownin Figures 1 and 2. This switch comprises a supporting base I which ispreferably, although not necessarily, of metal and is grounded asindicated at 2. A pair of insulators 3 and 4 are mounted upon the base Ifor supporting the live switch parts. The insulators 3 and 4 may be ofany standard construction and they are secured to the base in .a mannerwell known in the art. A hinge clip frame 5 is secured to the top of theinsulator stack 3 and provides a support for a line terminal 6, acontact clip 1, and a duplex switch blade 8. The switch blade 8comprises two blade members II and I2 which are of similar constructionand Which are secured together in spaced relationship by means of bladespacers I8 and I9. The hinge clip frame 5 is provided with twoupstanding arms I 0I0 on the outside of which the blade members II-I2are hinged by means of a hinge pin I3 and nuts I4. As shown, the bladestraddles the contact clip I, the two blade members lying upon theopposite sides of the clip. The clip I is of a constructionsubstantially similar to the construction of the clip which is engagedby the free end of the blade and which will be fully described as thedescription proceeds.

At the end of the blade remote from the hinge I mount a pair of lockbearing plates and 3|. The plate 30 is mounted on the inner side of theblade member I I and the plate 3| is mounted on the inner side of theblade member I 2. A pull ring 32 is pivoted between the lockbearing-plates by means of a hinge pin 33 which extends through theblade members II and I2, through the bearing plates 30 and 3|, andthrough the pull ring 32. Suitable nuts 34 and 35 are threaded on theopposite ends of the hinge pin 33 for securing the various partstogether. The hinge pin 33 together with the nuts 34 and 35 secure thefree ends of the blades together and prevent outward spreading of theblades. Spacer pins 2'! and 28 extend between the lock bearing plates 30and 3I and serve to maintain those plates suitably spaced apart andtherefore to maintain the spacing between the blade members I I and I2.The blade members receive the contact clip 25 between the pins I9 andthe pins 21-28 and maintain a firm engagement with the contact clip.

The blade engaging clip 25 is part of a contact terminal which ismounted upon the insulator 4. The terminal 40 is provided with a lineterminal M for receiving a line and with the clip 25 for establishingconnections with the switch blade. In addition a latch or pawl member ismounted on the contact clip frame. The pawl 45 is pivoted on the clipframe by means of a pin 46 and is biased to the locking position bymeans of a pair of springs 4I4'!. An extension 48, formed on the latch,limits the extent of turning of the latch in a counter-clockwisedirection as seen in Figure 5 by abutting against the clip frame. Thehook portion of the latch is adapted to engage the top of the pin 28 andto thus lock the blade against outward movement by any magnetic forcesthat may be developed due to the current flowing through the switch.During the switch closing movement the pin 28 rides on the taperedportion 49 of the latch, thus forcing it to turn slightly to the rightas seen in Figure 5 to permit the full closing of the switch. When theswitch reaches the full closed position the springs 47 turn the latch tothe position shown in Figure 5, thus locking the switch blade inposition. The pull ring is provided with a cam portion 50 which isadapted to force the latch or pawl 45 from its locking position to theunlocked position upon the initial pulling upon the ring to open theswitch. More will be said of this as the description proceeds.

An explanation will now be given of the construction of the contactingportion of the contact clip. The clip comprises a pair of arms and 52extending from the base of the con-. tact clip frame in spacedrelationship and secured together at opposite ends by means of abridging portion 53 formed integrally with both of said arms. Betweenthese two walls and on opposite sides of the center of the contact clipare mounted two rows of spring contact wires, said two rows beingindicated at 55 and 56, respectively. A

row of holes is drilled through the base of the.

' 5i and 58. The rows of wires are indicated at 55 and 56, respectively.After both rows of wires have been pressed into the holes and properlyaligned they are secured in place and in good electrical contact withthe base by peening the metal of the base around the wires at the points5? and 58 Each wire has a loop portion or eye formed therein asindicated at 59 and when the wires are initially inserted into thedrilled holes they assume a position such as is indicated in dottedlines of Figure 4 due to the fact that the drilled holes are at an angleto the vertical. In the assembly of the contact clip the wires of therow 55 are pressed inward toward the center at their free end and a pin60 is passed through holes in the walls 5| and 52 of the contact clipand through the loops of the respective wires of the row 55, thusretaining these wires in the position shown in full lines in Figure 4 ina prestressed condition. They are held in this position under springtension due to the resilience of the material of which they are made. Ina like manner the row of wires 56 is retained in the inward position bymeans of a pin 6| which is inserted into position in the same manner asis the pin 60. Washers are strung on the pins 60 and 6| between thecontact wires to prevent the contact wires from being sprung sidewayswhen the blade is being closed. 'When the contact wires are in thisposition it is to be noted that they extend transversely beyond the edgeof the walls 5| and 52 of the switch clip. There are a number ofpractical advantages in placing these wire fingers 55-56 under initialtension or prestress. First, by bending these spring fingers, such as 55or 56, from the dotted line position in Figure 4 to the full lineposition there shown, a certain prestress or inherent stress due to thedeflection is provided. In other words, when the blades l|--i2 come downover the wires 55- -56, the blades need to displace the spring fingersonly enough to force the loops 59 free of contact with the back sides ofthe pins 60 and 6|, and the pressure is as great as though the bladehad. actually forced conductivity and heat radiation.

In practice, this means that the blades engage the ends of the springfingers at a very low angle,

.and closing of the blade is surprisingly easy. The

amount of effort or work required to close the switch is less with theprestressed contacts than is required where the blades must displace thespring contact to gain the necessary stress required.

In addition, the switch with prestressed contacts is more compact andeconomical of material than prior switches. Also, in the case of a rowof contacts, such as 55 or 56, the contacts of each row are held inaccurate alignment by the common restraint of the pin 60 in case of therow of springs 55 and the pin 6|, in case of the row of springs 56.

Any desired degree of prestressing (within the limits of the design) maybe provided by changing the angle at which the holes are directed.

It is to be noted that the upper portion of the side walls 5i and 52 aretapered or curved inwardly as indicated at 55 and 56. said taperedportions merging with the bridge portion 53. This tapered nose portionserves as a guide for guiding the switch blade as it is moved into thefull closed position. The switch blade-members H and i2 are in generalflat but the contacting portion of the blade, that is, the portion ofthe blade that engages the contact wires, is made convex as indicated at61 and 68. When the switch blade is moved to the closed position itforces the rows of contact wires 55 and 56 inward from the full lineposition shown in Figure 4 to the full line position as shown in Figure3. The contact wires exert an outward pressure against the innersurfaces of the duplex blade and each wire is free to make a contactwith and exert its pressure against the surface of the blade entirelyindependent of the action of any of the other contact wires. It will befurther noted that when the blade is in its closed position the contactwires are approximately perpendicular to the base and that the portionsof the blade members which are opposite the contact wire present a verysmall contact area to them due to the convex surface of the blade at thecontacting portion. This arrangement insures contact being made at thecenter of the blade, thus using the material of the blade efiicientlyfor both electrical The use of many wires in parallel to carry currentfrom the switch blade to the clip base also uses the electricalconductivity of material efficiently and permits free circulation of airaround the clip and the blade. The engagement of the convex surface ofthe blade, such as l2, crosswise with the cylindrical wire, such as 56,is geometrically a 'point only. In practice, it is an exceedingly smalltion and a convex surface on the blade produces a switch contact that isself-cleaning and not readily thrown out of alignment. During theclosing motion of the blade the convex surface of the blade restsagainst the contacting portion of each of the spring contact wires inthe respective rows of wires with a considerable pressure at the pointof contact due to the fact that the area of contact with each wire isvery slight. Thisrub bing action serves to scram clean the contactingpoint of the blade as well as the contacting points of the wires, thuseliminating the resistance that would otherwise be present due to theformation of acoat of oxide or other impurities.

A reenforcing web I0 of a substantially inverted channel-shaped crosssection extends between the walls 5| and 52 of the clip, being formedintegrally therewith. In addition the wall 52 of the clip has a slotformed therein as indicated at H for permitting the locking latch toswing about its pivot to the right as seen in Figure 5.

The contact I is of a construction substantially identical to thecontact 25 previously described, difiering therefrom in that since nolatch such as the latch 45 is provided adjacent this contact clip it isnot necessary to provide the wall corresponding to the wall 52 with anopening wherein that latch may swing. The switch blade members II and I2are convex at I5 and I6 adjacent the contact clip I in the same manneras adjacent the contact clip 25. As a result of the provision of thecontact clip I the hinge I3 of the blade is not required to carrycurrent. It is also to be noted that a rather wide surface is providedbetween the switch blade members and the arms ID to which the blademembers are hinged, thereby rendering it diflicult for the blade to beforced out of alignment.

To open the switch a switch stick of a standard construction is used.The stick is provided at its end with a prong which is inserted into theeye of the pull ring 32 and a pull is exerted in a direction to open theswitch. Since-the switch is locked by the latch 45 against opening, thepull ring swings about the hinge pin 33 in a clockwise direction. Thecam portion bears against the tapered surface 49 of the latch 45 andforces the latch to move to the right as seen in Figures 2 and 5. Uponcontinued movement of the cam portion 50 the latch is released fromengagement with the pin 28 so as to permit opening of the switch. Thecam portion 50 moves into abutment with the pin 28 thereby preventingfurther turning of the pull ring about its pivot 33. Continued pullingon the pull ring 32 results in the swinging of the blade about its pivotto open the switch. I

Reference may now be had more particularly to Figure 8 showing asomewhat modified form of contact clip for use in a switch such as isshown in Figure 1. This contact clip may be used adjacent the hinge oradjacent the free end of the blade. Instead of using separate wires inthe opposite rows and 56 as in the previous construction the oppositewires of the two rows are, in this construction, integral. Each one ofthe wires comprises a loop 80, the. opposite ends of which are insertedinto the openings 51 and 58 in the same manner as previously described.This includes the prestressing or placing of the spring wire loop underinitial stress. This prestressing is secured by drilling the holes inthe base not vertical to the face, but at a slight angle to thevertical. side of Figure 8 are drilled with the axis sloping outwardlyaway from the vertical to the right, and the holes on the left hand sideare similarly drilled with their axes sloping outwardly away from thevertical toward the left. When the ends of the shanks 8|, 82 are broughtinto registration with the corresponding drilled holes, they may beforced into the holes by endwise thrust. The inclination of the holesguides the extremities toward each other, producing a tendency to bulgethe wires away from each other in the middle. This prestressing may befurther accentuated by forming the loop initially with the sides orshanks diverging from each other,

i. e., lying farther apart than the distance be-' Thus the holes at theright hand tween the holes into which these ends are forced. This wire80 is in general flexible and the two sides 8I and 82 thereof correspondto the two wires 55 and 56 of the switch previously described. It is tobe understood that a large number of wires such as the wire 80 are usedin this clip, one wire for each pair of holes 51 and 58 of Figure 6. Thewires are spaced from one another by washers, as in the previousconstruction. The washers are held on a pin 84 that extends between theside walls 5I-52 of the clip and around which the wires 80 are looped.

In Figure 9, I show a modified form of binge clip for a switch of thekind previously described. The blade 8', which is of a constructionsubstan tially the same as the blade 8 of Figures 1 and 2, is hinged tothe hinge clip frame by means of a hinge pin 85 which passes through thetwo blade members and through a pair of arms 86 on the hinge clip and issecured in place by means of a nut as indicated at 81 and a similar nuton the opposite side of the hinge clip frame. Rows of contact wires suchas indicated at 55 or 56 of the switch previously described are locatedon the opposite sides of the arms 86, one row being indicated at 88 and89. Two sets of rows of contact wires such as the rows 88 and 89 arelikewise located for engagement with the opposite blade member of theduplex blade 8. The hinge contact clip is provided with a stop 90 forlimiting the extent of opening movement of the switch blade to aposition at right angles to its full closed position. This form of hingecontact clip may be used for a double throw switch by merely omittingthe stop 90 and providing two free contacts like that shown in Figure 5on opposite sides of and in line with the hinge contact and each other.

Reference may now be had more particularly to the switch shown inFigures 10 and 11. This switch, as the previous switch, consists of ahinge terminal clip and a contact terminal clip mounted upon insulators3 and 4 which are themselves supported upon a base I as previouslydescribed. A duplex switch blade I00, comprising blade members IM andI02 secured together in spaced relation, is hinged by means of a pin I04and is adapted to be swung into engagement with a terminal clip I05. Thehinge contact I06 is shown in section in Figure 12, from which it may beseen that it is similar in a good many respects to the terminal clippreviously described.

The hinge terminal I06 has a bottom portion I01 into which are securedtwo rows of spring wire contacts indicated at I08 and I09 respectively,those contacts being secured in place in the same manner as are thespring wire contacts of the clip previously described. These spring wirecontacts are considerably shorter than the spring wires of the contactclips previously described,

and are secured in place at their opposite ends by means of pins H0 andIII which pass loosely through eyes formed in the wire, the eyes orloops in the wire being of an appreciably greater diameter than thediameter of the pins. The contact wires are spaced from one another bymeans of washers II 5, thereby preventing the ends of the wires I08 andI09 from sliding along the pins H0 and III during the closing movementof the switch blade. The contact clip is further provided'with a topportion III in which are mounted depending spring wires H8 and H9, saidwires being arranged in the same manner as are the rows of wires I08 andI09. It is to be noted that the wires in the four rows I08, I 09,

I I8 and H9 are mounted so as to be normally disposed at an angle to thevertical, the drilled holes in the contact clip and into which the wiresextend being preferably at an angle of about 4 15' to the vertical,although any other angle may be selected. The pins H and III areprovided for the set of spring contact wires I09 and H0 andcorresponding pins I20 and I2I are provided for the other set of thespring contact wires. These pins hold the contact wires in a positioninward towards the center of the contact clip as compared to theposition that they would naturally assume, due to their mounting in thedrilled holes in the contact clip casting, in the absence of these pins.In this construction the switch blade members IOI and I02 may be madeflat at their contacting portion with the springs. The contact clip Iwith which the opposite end of the switch blade engages is of aconstruction substantially similar to the contact clip I06 abovedescribed, difiering therefrom mainly in that the last mentioned contactclip is provided with a gradually upwardly and inwardly tapering guidingportion I25. The guiding portion I25 serves to guide the switch blade inposition since it is tapered and enters into the space between the blademembers MI and I02. The terminal upon which the clip I05 is mounted isprovided with a locking latch or pawl 45, and the blade is provided witha pull ring 32, both being of a construction such as has been previouslydescribed. The latch and the pull ring are effective to control thelocking and unlocking of the switch blades. vIn order to facilitate theguiding of the switch blade members into the switch closed position theends of the blades at the points along their lengths where they engagethe contact clips are beveled as indicated by the reference numeralsI21-I21.

The manner of operation of this switch is substantially similar to thatof the previously described switch and a further explanation is notbelieved to be necessary at this point.

Reference may now be had to the switch shown in Figures 15 and 16. Thisswitch comprises a pair of insulators 3 and 4 supported in the mannershown in Figure 2. -A hinge terminal I35 is mounted upon the insulator 3by means of bolts I36. The hinge terminal includes a contact tongue I31formed integrally therewith. A support comprising a pair ofsubstantially rectangular arms I40-I40 is provided, and it is to thissupport that the switch blade I45, comprising the blade members I46 andI41, is hinged. The supports I40 are secured to the opposite sides ofthe hinge clip I35 by means of screws I4I.

A description will now be given of the duplex blade I45. This bladecomprises two blade members I46 and I41 of similar construction. Each ofthese blade members comprises a channel I48 between the webs of whichare located laminations I49 spaced apart by washers or the like. Thelaminations comprise thin strips of copper or the like of the generalshape shown in Figure 16a. The channels I46 and I41 are secured togetherin spaced relationship about midway of their length by a pair of platemembers I50 and I5l and a number of pins or rivets I52 which extendbetween the plate members and through the flanges of the channels andalso serve to secure the laminated strips I49 and the washers I55 to thechannels. The rivets I52 prevent movement of the midpoints of thelaminations within the channels. The laminations are secured to thechannels at the opposite ends thereof by means of rivets I60 and NH. Therivets extend through'the flanges of the channels and throughwashersthat space the laminations from one another. Each of thelaminations has a'hole formed therein through which the rivet passes,the hole being of an appreciably larger diameter than the diameter ofthe rivet as may be clearly seen in Figure 20, so that the end of eachlamination has a certain limited freedom of motion with reference to therivets I60 and I6I. It is to be noted that the edges of the laminationsare considerably spaced from the web of the channel members I41 and I46at the two ends of the switch blade members. As a result there is acertain amount of give in each lamination if a force is applied theretoat the point indicated at I65 or I66, tending to force it toward the webof the channel. This give is possible due to the fact that the holes inthe laminations at the points where the rivets I60 and NH are locatedare of, a considerably larger diameter than the diameter of the rivets.

The channels I46 and I41 are hinged to the frame arm I40 by means ofpins indicated at I66. The two channels I46 and I41 are secured togetherat their opposite ends by means of the pull ring I10 which is providedwith a pair of arms I12 and I13 which are secured to the outer sides ofthe channels I46 and I41 respectively. Thus the pull ring not onlyserves as a means for opening and closing the switch but also as a meansfor securing the two channel members together in spaced relationship.Each of the arms I12 and I13 is provided with a downwardly extendingtapered guiding portion I14, which may be seen more clearly in Figure19, for the purpose of facilitating the guiding of the switch blade onthe two sides of the contact clip I10. The contact clip I18 is a part ofthe terminal I80 that is secured to the insulator 4. The terminal on theinsulator 4 and the terminal on the insulator 3 are each provided withlugs for receiving a line conductor in the same manner as are theterminals on the switches previously described. The distance between theextensions I65 of the laminations on the opposite blade members I46 andI41 when the switch is open isless than the thickness of thecontact clipI16. The contact clip is tapered at its edge so as to facilitate theguiding of the switch blade members into engagement with it and as theswitch is closed the contact clip member causes a spreading of thelaminations at the point I65. The laminations make contact with the clipand slide along the same. There is a considerable amount of pressurebetween the laminations and the contact clip due to the fact that thelaminations are being spread apart out of their normal position. As aresult there is a considerable scraping or cleaning action brought aboutby the movement of the blade members to the closed position. As a resultthe contacting surfaces that are in engagement with one another when theswitch is closed are quite clean and excellent contact is established.The same action takes place at the extensions I66 adjacent the hingeportion of the switch blade, hence at this point also there is bound tobe good electrical contact with the ter-' minal I31.

It is to be noted that each lamination makes contact with the contactclip at a very small area so that the unit pressure at that area. isrelatively large. The spacing of the laminations from one another servestwo main purposes. Should there be an appreciable amount of foreignmatter upon the edges of the laminations or upon the contact clip then,due to the spacing between the laminations, this foreign matter may bereadily scraped away, thereby tending to maintain a clean contactingsurface. The second main function is that of increasing the heatradiation properties of the switch blade.

In compliance with the requirements of the patent statutes I have hereinshown and described a few preferred embodiments of my invention. It is,however, to be understood that the invention is not limited to theprecise embodiments herein shown, the same being shown for illustrativepurposes only.

What I consider new and desire to secure by Letters Patent is:-

1. A switch contact comprising a plurality of parallel rows ofsubstantially parallel spaced wires, and a support for both ends of, thewires, one of said ends being permitted a limited amount of motiontransversely of the rows.

2. An electric switch contact clip having a base portion, a pair ofspaced arms extending therefrom, and .a row of spring contacts held atone end in said base and held at their other end between said arms.

3. An electric switch contact clip having a base portion, a pair ofspaced arms extending therefrom, and a set of rows of spring contactsheld at one end in said base and held at their other end between saidarms by means including a lost motion connection whereby the springshave a limited freedom of motion at their said other end.

4. A contact housing open at its sides, a plurality of spring contactwires extending lengthwise of each of the open sides and having aportion thereof extending beyond the open sides of the housing, and aswitch blade including portions adapted to straddle the housing andsimultaneously engage with the contact wires on each side of thehousing.

5. A contact housing open at its sides, a plurality of spring contactwires extending lengthwise of each of the open sides and having aportion thereof extending beyond the open sides of the housing, and aswitch blade including portions adapted to straddle the housing andsimultaneously engage with the contact wires on each side of thehousing, said contact housing including means for guiding a switch bladeinto its closed positions straddling the housing.

6. A switch including a plurality of spaced parallel rows of springcontact wires, and a pair of mechanically and electrically connectedswitch blade contact members slidable into and out of simultaneousengagement with the opposite sides of the two rows of contact wires.

7. A switch including a plurality of spaced parallel rows of springcontact wires, and a pair of mechanically and electrically connectedswitch blade contact members slidable into and out of simultaneousengagement with the opposite sides of the two rows of contact wires, thecontacting portion of the blades being convex.

8. A switch including a plurality of spaced par allel rows of springcontact wires, and a pair of mechanically and electrically connectedswitch blade contact members slidable into and out of simultaneousengagement with the opposite sides of the two rows of contact wires, thespring contact wires being bowed towards the blade members to present apoint contact thereto.

9. A switch including a plurality of spaced parallel rows of springcontact wires, and a pair of mechanically and electrically connectedswitch blade contact members slidable into and out of simultaneousengagement with the opposite sides of the two rows of contact wires, thecontacting portion of the blades being convex and the spring contactwires being bowed towards the blade members to present a point contactthereto.

10. An electric switch comprising a contact clip having a base portionand a pair of spaced arms extending therefrom, a set of rows of springwire contacts held at one end in said base and held at their other endbetween said arms by means including a lost motion connection'wherebythe springs have a limited freedom of motion at their said other end, aswitch blade having cooperating contact portions adapted to straddleboth sets of rows of contacts, and guiding means for guiding theblade-into engagement with the spring wire contacts.

11. An electric switch including a contact member and a blade member,said blade being mounted for sliding movement onto and along the contactmember for establishing contact therewith, one of said memberscomprising a large number of narrow flexible pieces bowed adjacent oneend towards engagement with the other member and engaging said othermember at their bowed portions, and a lost motion connection includingpin means passing loosely through the flexible pieces at their endsadjacent their bowed portions and at right angles to their direction offiexure for securing them together while permitting them a limiteddegree of relative movement at the pin.

12. A contact clip comprising a top and a bottom, a long narrow springcontact extending up ward from the bottom of the clip towards the top,and a second long narrow spring contact extending downward from the toptowards the bottom, both of said contacts being electrically connectedand constituting the contacting portions of the single contact clip.

13. A contact clip comprising a top and a bottom, a row of long narrowspring contacts extending upward from the bottom of the clip towards thetop, and a second parallel row of long narrow spring contacts extendingfrom the top towards the bottom, all of said contacts in both rows beingelectrically connected and constituting the contacting portions of thesingle contact clip.

14. A switch including a contact clip comprising a top and a bottom, along narrow spring contact extending from the bottom of the clip towardsthe top, a second long narrow spring con tact extending downward fromthe top towards the bottom, both of said contacts being electricallyconnected and constituting the contacting portions of the single contactclip, and a switch blade movable in a direction extending lengthwise ofthe contacts and sliding along and lengthwise of the contacts into theclosed position.

15. A switch including a contact clip comprising a top and a bottom, arow of long narrow spring contacts extending upward from the bottom ofthe clip towards the top, a second parallel row of long narrow springcontacts extending from the top towards the bottom, all of said contactsin both rows being electrically connected and constituting thecontacting portions of the single contact clip, and a switch blademovable in a direction extending lengthwise of the contacts and slidingalong and lengthwise of the contacts into the closed position.

16. A switch including a contact clip comprising a top and a bottom, arow of long narrow spring contacts extending upward from the bot- 75 tomof the clip towards the top, a second parallel row of long narrow springcontacts extending from the top towards the bottom, all of said contacts in both rows being electrically connected and constituting thecontacting portions of the single contact clip, and a switch blademovable in a direction extending lengthwise of the contacts and slidingalong and lengthwise of the contacts into the closed position, saidblade being convex at the portion thereof that engages the contacts. a

17. A switch blade including a channel frame and a plurality oflaminations held between the flanges of the channeland spaced from theweb thereof.

18. A switch blade including a channel frame and a plurality oflaminations extending substantially the full length of the frame heldbetween the flanges of the channel, said laminations constituting thecontacting portion of the blade.

19.- A switch blade including a channel frame and a plurality oflaminations held between the flanges of the channel and spaced from theweb 7 thereof, and a pivotal support for the channel frame.

20. A switch blade including a channel frame and a plurality oflaminations held between the flanges of the channel and spaced from theweb thereof, said laminations lying in spaced planes parallel to theflanges of the channel.

21. A switch blade including a channel frame and a plurality oflaminations held between the flanges of the channel and spaced from theweb thereof, said laminations lying in spaced planes parallel to theflanges of the channel and constituting the contacting portion of theblade.

22. A switch blade including a channel frame and a plurality oflaminations held between the flanges of the channel and spaced from theweb thereof, said laminations lying in spaced planes parallel to theflanges of the channel, and washers between the laminations.

23. A switch blade including a channel frame and a plurality oflaminations held between the flanges of the channel and spaced from theweb thereof, said laminations constituting the contacting portion of theblade, and washers between the laminations.

24. A switch blade including a channel frame and a plurality oflaminations held between the flanges of the channel and spaced from theweb thereof, and a pivotal support for the channel frame, saidlaminations being secured to the channel at points spaced from thepivotal support and being free of the channel adjacent the support.

25. A knife switch comprising a hinge contact, a switch blade memberpivoted thereto, and a contact clip member adapted to be engaged by theblade member by a motion whereby the two members slide into one another,said two members sliding along and into one another upon continuedmovement of the blade member after it initially contacts with the othermember, said blade member comprising a large number of relatively thinparallel laminations the contacting edges of which are in the plane ofmovement of the blade and engage with the contact clip member by ascraping movement edgewise of the laminations whereby portions of theclip are successively scraped by the successive laminae.

26. A knife switch comprising a hinge contact, a switch blade memberpivoted thereto, a contact clip member adapted to be engaged by theblade member by a motion whereby the two members slide into one another,said two members sliding along and into one another upon continuedmovement of the blade member after it initially contacts with the othermember, said blade member comprising a large number of relatively thinparallel laminations, the contacting edges of which are in the plane ofmovement of the blade and engage with the contact clip member by ascraping movement edgewise of the laminations whereby portions of theclip are successively scraped by the successive 1aminae, and washersbetween said parallel contacting members for spacing them apart topermit the circulation of air between said parallel members.

27. A switch comprising a hinge contact, a switch arm member pivotedthereto, and a contact clip member adapted to be engaged by the armmember by a motion whereby the two members slide into one another, saidtwo members sliding along and into one another upon continued movementof the arm member after it initially contacts with the other member,said clip member comprising a large number of relatively thin and narrowparallel spring contacting wires arranged in two spaced rows on oppositesides of the arms for simultaneous engagement by the arm member.

28. A switch comprising a hinge contact, a switch arm member pivotedthereto, a contact clip member adapted to be engaged by the arm memberby a motion whereby the two' members slide into one another, said twomembers sliding along and into one another upon continued movement ofthe arm member after it initially contacts with the other member, saidclip member comprising a large number of relatively thin and narrowparallel spring ,contacting members arranged in two spaced rows andflexible towards and away from one another for simultaneous engagementby the arm member, and spacing means between the parallel springcontacting members of each row for spacing them apart to permit thecirculation of air betweenv them.

29. Aswitch contact comprising a mounting base having at least twoparallel rows of wire receiving holes formed therein, parallel springcontact making wires having their ends inserted into said holes andtightly held therein, the op- ,posite ends of the wires having a limitedfreedom of motion, and a pin extending parallel to said rows of'holes,the opposite ends of said wires being loosely looped around said pin.

30. A switch contact comprising a mounting base having at least twoparallel rows of wire receiving holes formed therein, parallel springcontact making wires having their ends inserted into said holes andtightly held therein, the opposite ends of. the wires having a limitedfreedom of motion, a pin extending parallel to said rows of holes, theopposite ends of said wires being loosely looped around said pin, andmeans extending beyond said looped ends of the wires for guiding a.blade into wiping contact making engagement with the contact wires.

31. A switch comprising a plate-like switch contact, a metallic basemember, and a row of wire springs disposed in parallel planes supportedas cantilevers in said base, each of said springs having a surface ofdouble convexity formed by bending of the wire whereby each wire isadapted to provide a substantially single point contact for engagementwith said plate-like switch contact.

32. In a switch, a platelike contact member adapted to move in apredetermined plane, a cooperating contact device comprising a baseextending approximately in a plane substantially transverse to the firstplane, a row of spring rods supported as cantilevers extending insubstantially parallel planes which are approximately normal to thefirst plane, said rods having surfaces of double curvature remote fromthe base defining contact points adapted to engage said plate-likecontact member at substantially single points only, and means tending tohold said plate-like member in engagement with said double curvedsurfaces against the spring of said rods.

33. In a contact making device, a blade having a surface generated by amoving line always parallel to a given line, a contact comprising abase, a row of spring rods mounted as cantilevers in said base, saidrods being adapted to engage said surface, said engagements beingconfined substantially to single points by two degrees of curvature ofthe elements making up said engaging surfaces, at least one degree ofcurvature appearing on the surfaces of said rods.

34. A multiple high pressure ventilated contact comprising a basemember, a series of resilient rodlike elements mounted on said memberfor cantilever support thereupon, said elements having contact portionsof double curvature, and intermediate spring portions between said baseand said contact portions.

35. In combination, a stationary base plate, a blade member movable in aplane substantially normal to the base plate, a series of rodlikeconductors disposed in a row, each conductor comprising an anchoringportion at one end by which it is fixed to and mounted on the baseplate, a contacting portion at the other end for engaging the blade, andan intermediate resilient portion for allowing lateral movement of saidcontacting portion transversely of the row, said conductors being spacedapart for individual mechanical action and to promote ventilation, saidcontacting portions being spaced from said base plate by saidintermediate portions.

36. In combination, a base plate, a blade member movable in a planesubstantially normal to the base plate, a series of aligned rodlikeconductors, each conductor comprising an anchoring portion by which itismounted on the base plate, a contacting portion for engaging the blade,and an intermed ate resilient portion spacing the contacting portionfrom the base plate, said conductors being spaced apart for individualmechanlcal action and to promote ventilation, the engagement of eachrodlike conductor with the blade being limited substantially to singlepoint contact by virtue of the two engaging surfaces possessing twodegrees of convexity, said blade and said contacting portion havingwiping engagement.

37. In combination, a blade movable in a definite plane, a cooperatingcontact comprising a base plate, a row of resilient rodlike conductorshaving anchoring portions disposed in a line parallel to said plane,said conductors having contacting portions adapted to engage said bladesubstantially at single points only with wiping engagement, saidsubstantially single point engagements being produced by virtue of theshape of the engaging surfaces, which surfaces contain two degrees ofconvexity, said conductors having intermediate resilient portionsbetween said anchoring portions and said contact portions extendingsubstantially normally to the surface of the base plate to which theyare anchored and serving to space them from each other.

38. In a switch, a rigid contact member, a yielding contact devicecooperating with said memberand comprising a plurality of double convexcontact elements having separate rodlike stems and a rigid base to whichsaid stems are rigidly anchored, said elements and said member havingsubstantially single point contact, and the pressure of each elementagainst the member being individually controlled by the correspondingrodlike stem, said rodlike stems serving as individual cooling means forthe heat evolved by current flow through the corresponding contact, saidstems extending substantially normally to the surface of the base andserving to space the double convex contact elements from the base.

39. A contact making device comprising a rigid contact member having acontact surface, a yielding contact member consisting of a rigid base, aseries of wires disposed in a row with one end of each rigidly anchoredfor cantilever support of the outer end from the base and disposed outof contact with each other for individual mechanical action and topromote cooling, said wires having transversely bent portions providingdouble curved contacting portions which are adapted to have eachsubstantially a single point engagement with the contact surface, saiddouble curved portions being spaced from the base to permit resilientlateral deflection thereof.

40. A contact making device comprising a rigid contact member having acontact surface, a yielding contact member consisting of a rigid base, aseries of wires with one end of each rigidly anchored for cantileversupport of the outer end from the base and disposed out of contact witheach other for individual mechanical action and to promote cooling, saidwires having transversely bent portions providing double curvedcontacting portions which are adapted to have each substantially asingle point engagement with the contact surface, and means for holdingsaid wires in prestressed condition.

41. In combination, a stationary contact device having contacting meansfacing in opposite directions, a movable contact device also havingcontacting means facing in opposite directions for engagement with thefirst means, said stationary contact device comprising a base, a seriesof spring fingers mounted for individual play and cooling, said springfingers comprising rod-like elements of cross section presentingtransverse convexity to the first of said contact means, said springfingers having bendsproviding convexity in a longitudinal directionwhereby engagement of the spring fingers and the contacting means issubstantially at single isolated points.

42. A switch contact member comprising a substantially horizontalsupporting base, a plurality of substantially vertically disposed springwires of relatively small diameter having their lower ends fixedlysecured to said base to provide a cantilever support, and having theirupper ends free to move laterally in making contact, and means to limitthe play of the outer ends of said wires in making and breaking contact.

43. In combination, a U-shaped wire contact member having the ends ofthe limbs thereof rigidly connected, a cooperating contact member havingtwo spaced contact surfaces facing each other, and means for forcingsaid two surfaces upon opposite sides of said U-shaped wire contactmember.

44. In combination, a base member, U-shaped wire contact members thefree ends;of which are rigidly secured in said base member, acooperating contact member having two spaced contact surfaces'facingeach other, and means tending to hold said surfaces in contact with saidU- switch blade on either side and free to move laterally in makingcontact, and their intermediate portions constituting substantiallystraight line extensions of the secured ends and providing cantileversupport for the outer ends.

46. A switch contact comprising a substantiall horizontal supportingbase, and a plurality of hairpin-shaped wire contacts arranged insubstantially parallel rows and having their free ends fixedly-securedto the base, and their outer ends curved to provide a point contact witha switch blade on either side and free to move laterally in makingcontact, and their intermediate portions constituting substantiallystraight line extensions of the secured ends and providing cantileversupport for the outer ends, and means for protecting said hairpins fromdistortion beyond the limits of their resiliency on closing of theswitch.

47. A switch contact comprising a substantially horizontal supportingbase, and a plurality of hairpin-shaped wire contacts arranged insubstantially parallel rows and having their free ends fixedly securedto the base, said wire contacts being adapted to be engaged uponopposite sides by aswitch blade and being free to move laterally inmaking contact therewith, the intermediate portions of said contactsconstituting substantially straight line extensions of the secured endsand providing cantilever support for the outer ends.

48. The combination of a contact device comprising a base member, andcontact fingers comprising a row of parallel individual wires which havecontact portions bent to the same form to provide free end portionswithdouble curved surfaces, said wires having their opposite end portionssubstantially parallel to each other and extending in the same directionand being fixed in said base member, whereby thelcontact fingersconstitute cantilevers for supporting pressure of a cooperating switchmember upon said double curved surfaces, a cooperating switch memberhaving a contact surface engaged along a substantially straight lineby-points on said double curved. surfaces when the member and contactfingers are in engagement, and means for guiding said contact fingersand said switch member;

into wiping contact making engagement.

'49. In a switch, a pair of relatively movable rying said contactors,said cantilevers being 50. A switch contact comprising a rigid framemember, a spring wire contactor having a contacting portion and havingoneend anchored rigidly in said frame member, said wire contactorbeingdeflected from normal unstressedposition to stress the same, andmeans mounted on the frame back of said contacting portion for holdingsaid wire contactor in said deflected and stressed position.

51. A switch comprising an arm guided for movement in substantially apredetermined plane, a contact member adapted to be engaged by the armwith a wiping motion when the arm isv moved to switch closing position,said contact member comprising a base and a plurality of prestressedcontact fingers having contactingportions adapted to be engaged by thearm.

52. In a switch, the combination of a first con tact comprising a pairof spaced contact surfaces supportedin fixed positionrelative toeachother and a-second contact comprising a rigid support,- and contactfingers .arranged inrows, said'flngers being fixed at one end to saidrigid support and extending in the same direction and having contactsurfaces adjacent their'outer ends coacting with the contact surfaces onthe first contact, the contact surfaces on one of said contacts beingconvex with respect to the other to reduce the area of actual engagementwith the other; said contact surfaces of one contact facing away fromeach other and the contact surfaces of the other contact facing towardeach other.

53. The combination of claim 52 wherein the fingers are resilientlystressed and means including lost motion connections for limiting thetraverse of said contact fingers whereby they are maintained under saidstress.

54. The combination of claim 52 wherein the relative movement of saidcontacts to open and close the switch is in a line substantiallylongitudinal of said contact fingers.

55. A switch comprising a pair of switch members between which there isrelative movement.

small area at their other ends, said high pressure contact surfacesfacing in opposite directions, whereby they are adapted to engage thecontact surfaces of the said one member.

56. The switch of claim 55 further characterizedbylost motion means forlimiting the separation of the fingers from each other.

57. In combination, a contact member comprising a pair of spaced contactsurfaces held substantiallyrigidly in spaced relation to each other, acooperating, contact member comprising a rigid metallic supportingelement having a plurality of spring fingers rigidly anchored to saidsupporting element at one end and having their other ends extendingsubstantially parallel to each other, and lost motion means at the outerends of thefingers forlimit'ing the movement of the gngers with respectto each other, said fingers being urged resiliently against said lostmotion. means when the contact members are separated and being urgedresiliently against said contact surfaces of. said first member whensaidmembers are in engaging relation.

58. A switch comprising a relatively movable element and a relativelystationary element, the relatively stationary element comprising a rigidmember having contact faces upon opposite sides of a median plane, therelatively movable element comprising a movable frame member the medianplane of which is adapted substantially to coincide with the medianplane of the stationary element when the elements are brought intoengagement, the frame member comprising a substantially rigid anchorage,a pair of rows of spring fingers fixed to said anchorage and havingcurved contact ends, the contact ends of said rows respectively engagingopposite faces of the said rigid member, and a transverse bar for eachrow, each bar having lost motion connection with the spring fingers ofthe corresponding row.

59. In a switch comprising a metal mounting plate and insulatorsextending from said plate, the combinationof stationary contact membersmounted on said insulators, one member comprising a base portion havinga hinge element and adjacent thereto two rows of parallel wires anchoredrigidly at one end and-having their outer ends disposed substantially inalignment, said wires being yieldable transversely of the respectiverows, the other member comprising a base portion and adjacent theretotwo rows of parallel wires anchored rigidly at one end and *aving theirouter ends disposed substantially in alignment, said wires beingyieldable transversely of the respective rows, and a switch arm pivotedat one end upon said hinge element, said arm having substantiallycylindrical contact surfaces engaging transversely of the wires of therows, respectively, at each end, whereby substantially point contactbetween the individual wires and the arm contact surfaces is secured.

60. The combination of claim 59, wherein the hinge element of the firststationary contact is disposed at one end of the corresponding row ofwires and wherein the second stationary contact has a locking element atone end of the corresponding row. of wires and the switch arm carries acooperating locking element and an eye member for operating the switcharm and for-releasing the locking elements.

61. The combination of claim 59 wherein the outer ends of the wires arebent into curves adapted to engage the transverse cylindrical contactsurfaces of the arm when the arm and the wires engage, whereby stubbingis prevented.

62. A switch comprising a base, two parallel rows of wire contactsrigidly anchored to the base, the individual wires being yieldabletransversely of their rows, respectively, and a cooperating switchmember comprising cylindrical surfaces each cooperating with a row, thelongitudinal axis of each cylindrical surface being transverse withrespect to the longitudinal axes of the contact portions of the wires,whereby two sets of high pressuremultipoint contacts are secured.

63. In a switch a relatively rigid contact member, and a relativelyyielding multiple contact member, said multiple contact membercomprising a rigid metal base, a plurality of flexible wires havingmounting ends rigidly fastened into the base for mechanical anchorageand for the conduction of current thereto, said first contact memberbeing movable endwise along the length of the wires to slidably engage alateral surface of the same, said wires having portions adjacent theirouter ends bent to provide limited engagement of each wire with thecooperating surface of the relatively rigid contact member, said wiresproviding multiple limited area high pressure contact engagement withsaid rigid contact member, said wires adjacent their points ofengagement with the rigid contact member being provided with means forlimiting the deflection of said wires in the direction of engagementwith said first member whereby said wires are held in prestressedcondition before engagement with the first member.

64. In a switch a relatively rigid contact member, and a relativelyyielding multiple contact member, said multiple contact membercomprising a rigid metal base, a plurality of flexible wires havingmounting ends rigidly fastened into the base for mechanical anchorageand for the conduction of current thereto, said first contact memberbeing movable endwise along the length of the wires to slidably engage alateral surface of the same, said wires having portions adjacent theirouter ends bent to provide limited engagement of each wire with thecooperating surface of the relatively rigid contact member, said wiresproviding multiple limited area high pressure contact engagement withsaid rigid contact member, and resilient means for backing up the outerends of the individual wires whereby each individual wire may exert 'agreater yielding contact pressure than it could support from themounting end alone.

65. In a switch a relatively rigid contact member, and a relativelyyielding multiple contact member, said multiple contact member compris-'ing a rigid metal base, a plurality of flexible wires having mountingends rigidly fastened into the base for mechanical anchorage and for theconduction of current thereto, said first contact member being movableendwise along the length of the wires to slidably engage a lateralsurface of the same, said wires having portions adjacent their outerends bent to provide limited engagement of each wire with thecooperating surface of the relatively rigid contact member, said wiresproviding multiple limited area high pressure contact engagement withsaid rigid contact member, resilient means for backing up the outer endsof the individual wires whereby each individual wire may exert a greateryielding contact pressure than it could support from the mounting endalone, and motion limiting means rigid with the base for limiting thedeflection of said wires individually within their elastic limits, saidmotion limiting means having lost motion connection with said individualwires to permit free motion within limits of the individual wires.

ALLAN RAMSEY.

